This invention relates to the structure and manufacture of a protective fabric suitable for use as a heat and flame barrier. More particularly, the fabric may be used to prevent the combustion of flammable materials by using the fabric as a barrier between the heat source and any flammable materials.
Various types of protective fabrics have been developed for use in applications in which fabric covered articles (e.g., upholstered articles or office panels) must be capable of withstanding exposure to heat and/or flame without combustion. For example, in upholstered aircraft seating, a heat resistant protective barrier fabric is typically provided between the outer upholstery fabric and the underlying flammable foam cushion to retard or prevent combustion of the cushion in the event of fire. Note, for example, U.S. Pat. No. 4,463,465 to Parker et al which discloses a barrier fabric which comprises an aramid fabric substrate and an outer aluminum foil layer. The use of an aluminum foil layer, however, has several drawbacks, namely the fabric has limited breathability and the cushioning aspects of the upholstered article are reduced.
U.S. Pat. No. 4,509,559 to Cheetham et al discloses an exemplary fire-resistant fabric used as a protective cover for hoses employed to transport inflammable liquids. The fabric comprises an innermost layer of a thermally intumescent material, an intermediate layer of a fabric impregnated with alumina trihydrate and an outermost polished metal sleeve. This fabric is resistant to fire but has very limited flexibility and formability, making it unsuited for many applications, such as with upholstery.
U.S. Pat. No. 4,569,878 to Barrall et al discloses a fire-resistant laminate material, useful as office partitions, comprising a series of layers of woven and non-woven synthetic material and glass which are bonded together with an intumescent composition comprising a metal oxide, calcium silicate and phosphoric acid. This fabric also has limited flexibility and breathability.
Another technique for producing a fire-resistant fabric for use as a flame barrier is to coat the fabric with a fire-resistant compound. Exemplary compounds include those based on an inorganic hydrated compound such as hydrated alumina, hydrated magnesia, magnesium oxychloride, hydrated zinc borate and hydrated calcium borate. Coatings of this type, however, leave spaces between the fibers of the fabric. These spaces or interstices potentially allow hot gases and/or flames to penetrate therethrough and ignite the underlying flammable material.